import 'package:flutter/material.dart';

class ContainerCase2 extends StatelessWidget {
  const ContainerCase2({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
        width: double.infinity,
        height: double.infinity,
        color: Colors.black,
        alignment: Alignment.center,
        child: Container(
          width: 300,
          height: 300,
          color: Colors.yellow,
          child: Text("测试"),
        ));
  }
}
